Hi Cindy,
The CP-51 is a big piece of machinery, and takes up quite a bit of space. It runs on 6 liters each developer and blix, but has an automatic replenishment system built in, which is optional on the CP-31. I love it! And a lot easier than dealing with drums, unless you are really patient, which I am not.

The chemistry can be left in the 51, there are floating lids available, but it is recommended to clean the tanks if the processor isn't used in more than a week.

So, if you have the space, I highly recommend the Fujimotos, they are easy to work on, reaaaaally dependable, and make processing a breeze. Omega Satter bought the analog division of Jobo, parts and support are available, but yes, a bit expensive, you can try and find a used processor on Ebay for parts if need be. I did.

And regarding the "retro" thing: it doesn't get any more retro than this place now, does it?

RA4 is ideally suited to automatic processing, as the processing times are fixed, and you can't improve or manipulate the results for improvement by altering the process.

There were many tabletop processors made for processing RC color paper, starting with EP-2 process, and these machines can also be used for RA-4.

Durst marketed a line of processors starting in the mid-1970's. They had a smaller machine designed to process 8 inch wide paper (8x10's) that was just a develop and blix machine, you still had to wash the prints and dry them.

Nutek then took over the line and made processors for RA-4 and Cibachrome (Ilfochrome). Some of these had wash/dry modules.

Fujimoto made a nice line of tabletop processors.

Durst again entered the market with the Durst Printo modular processors.

All of the above are tabletop roller-transport processors that operate with relatively small amounts of chemistry (for their maximum print size), some have automatic replenishment, some have wash/dry modules, and most important, ALL allow you to put a sheet in, close a lid and turn on the lights while the print is being processed. So, you can busy yourself with setting up the next neg to print, or you can leave the lights off, and make multiple prints of the same neg, feeding the paper in as quickly as the processor can take it.

Most, if not all, will take paper smaller than 8x10, but paper is not available smaller than 8x10, so you would have to cut it in your darkroom. The preferred technique is to use a step-and-repeat easel that allows you to make multiple-smaller images on one 8x10 sheet, then cut them apart after washing and drying. This makes it easy to make, say, a dozen wallets, or 4 3x5's, or a pair of 5x7's of the same image on one 8x10 sheet of paper.

RA-4 Processor

I'v had my DO-Mac processor for 8 years now. Adorama used to sell them for $1800 at the time. It comes set up for a slightly modified RA type chemistry and runs faster than the standard processing times. It also comes the gear and belt to convert to standard RA timing. The machine has only 6 moving parts, (all above fluid levels). The preset, but adjustable temperature control is easy to adjust and uses only 1 liter of dev and blix. It will process 16" paper (has 18" opening). (minimum length is 8 inches), but that is not a problem with a multi-print easel. It will also run B&W chemistry. standard developer and fixer. Finished prints drop into a holding tray (user supplied) with either RA stabiliser for wash-free printing or rinse water for wash up later after print session.